Yarn feeding method and apparatus for circular warp knitting machines

ABSTRACT

Certain groups of adjacent warp yarns are at times fed to the circular warp knitting machine at a different rate than the remaining groups of warp yarns to thereby vary the length of the stitch loops being formed and to fashion the tubular fabric while it is being knit. Pairs of warp yarn feeding rolls are drivingly interconnected and are arranged around the needle cylinder. One pair of rolls may be selectively driven at a different speed, relative to the other rolls to at times feed a selected group of warp yarns at a different rate and to at times feed all the warp yarns at the same rate.

' United States Patent I Nogues [451 Sept. 26, 1972 [s41 YARN FEEDINGMETHOD AND 1,072,715 6/1967 Great Britain ..66/178 R APPARATUS FORCIRCULAR WARP 1,109,788 4/1968 Great Britain ..66/132 KNITTING MACHINESOTHER PUBLICATIONS [72] Inventor: Fe denco. sanfeliu Nogues ,caneDarlington, Knitted Outerwear Times, May 27, 1968,

Diputaclon, 68 Barcelona, Spam VOL 37 N0 23 PP. 4O 22 Filed: Oct.27,1970 Primary Examiner-Wm. Carter Reynolds [21] Appl. No.: 84,432Attorney-Parrott, Bell, Seltzer, Park & Gibson 521 US. Cl. ..66/81,66/132, 66/189 1571 ABSTRACT [51] Int. Cl. ..D04b 25/02 Certain groupsof adjacent warp yarns are at times fed [58] Field of Search ..66/81, 86A, 132, 80, 8, 54, to the circular warp knitting machine at a different66/ 189, 87, 178 R rate than the remaining groups of warp yarns to Ithereby vary the length of the stitch loops being 5 References Citedformed and to fashion the tubular fabric while it is being knit. Pairsof warp yarn feeding rolls are UNITED STATES PATENTS drivinglyinterconnected and are arranged around the needle cylinder. One pair ofrolls may be selectively SChWab driven at a different p relative to theother rolls 2,004,260 6/ 1935 Welch et a1 ..66/81 X to at times f d a lt d group of warp yarns at a 3,479,841 1 1/1969 Kitahara et al. ..66/8 Xdifi t rate and to at times f d all the warp yams at 3,51 l NOgUeS..66/81 the same fate 3,566,621 3/1971 Perrier ..66/87 FOREIGN PATENTSOR APPLICATIONS 5 Claims, 5 Drawing Figures 315 1878 Great Britain..66/81 W6 W-Z C B 54 x f 7 Z 30 r T12 an 45 32 ll Q W WA Q Z 19 4e 18Z3 l9 l8 PATENTEUsms m2 v SHEEY 1 0F 2 INVENTOR:

RA co NOCa-UES I ATTORNEYS PATENTEDszrzsmz 7 3.693378 snmaur2 vINVENTOR: FEDERACO SANFEUU Nocruas mm g4 wwan l v ATTORNEYS YARN FEEDINGMETHOD AND APPARATUS FOR CIRCULAR WARP KNITTING MACHINES The presentinvention relates generally to a warp yarn feeding method and apparatusfor circular warp knitting machines of the type adapted to producetubular fabric for use as hosiery, panty hose, and the like, and moreparticularly to a positive yarn feeding means which may be operated tofeed certain groups of adjacent warp yarns at different rates from theremaining warp yarns-to thereby form stitch loops of different lengthsin selected courses and to fashion the tubular fabric while it is beingknit.

As disclosed in my U.S. Pat. No. 3,511,062, issued May 12, 1970, and mycopending application Ser. No. 773,995, filed Nov. 7, 1968 now US. Pat.No. 3,570,268, the warp yarns are divided into separate groups which arepositively fed to the needles by pairs or sets of feed rolls arrangedaround the needle cylinder. The sets of feed rolls are each driven atthe same rate so that all the needles form the same size stitch loop inany given course. While it is possible to change the rate of feed of allthe yarns as successive course are knit, it is not possible to vary therate of feed of a selected group of yarns to change the size of stitchloops formed by a particular group of needles. Thus, with this type ofyarn feeding arrangement, it is not possible to knit a curved tubularfabric or to knit one or more enlarged pockets long one side of thetubular fabric.

With the foregoing in mind, it is an object of the present invention toprovide a method and apparatus for positively feeding yarns to acircular warp knitting machine whereby the tubular fabric may be curvedwhile it is being knit or may be knit with one or more enlarged pocketsalong one side.

In accordance with this invention, means is provided for selectivelyvarying the rate of feed of a certain group of adjacent warp yarns sothat stitch loops of different lengths are knit in the same course. In apreferred embodiment of the invention, the yarn feeding means comprisesdrivingly interconnected sets of positive feed rolls supported aroundthe needle cylinder with a speed-change mechanism interposed betweencertain sets of the feed rolls so that the rotational speed of certainsets of the feed rolls may be varied at selected times during theknitting of the tubular fabric.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds when taken in connection withthe accompanying drawings, in which FIG. 1 is an isometric view of theupper portion of a circular warp knitting machine with the yarn feedingmeans of the present invention applied thereto;

FIG. 2 is an enlarged fragmentary isometric view looking in thedirection of the arrow 2 in FIG. I and illustrating a speed-changemechanism interposed between adjacent sets of feed rolls;

FIG. 3 is an enlarged fragmentary plan view of' the speed-changemechanism shown in FIG. 2, with parts in section to illustrate themanner in which the bevel gears may be selectively engaged to vary thefeed rate of adjacent feed rolls;

FIG. 4 is an isometric view of one type of tubular fabric which may beknit in accordance with the present invention; and

FIG. 5 is a view similar to FIG. 4 but schematically illustratinganother type of tubular fabric which may be knit in accordance with thepresent invention, and including an enlarged pocket on one side.

As illustrated in FIG. 1, the circular warp knitting machine includes amain base plate or bed plate 10 which supports a needle cylinder 11 in afixed position. Latch needles 12 are supported for simultaneous verticalmovement in the needle cylinder 11 and adapted to receive and formstitch loops of warp yarns which are divided into separate groups orsets, indicated at W-l through W-4. The warp yarns are fed-to theneedles 12 through one or more suitable yarn guide rings, only one ofwhich is shown at 14 in FIG. 1.

Means for positively feeding the different groups of warp yarns to thefeed rolls at varying rates and to therebyyvary the size of stitch loopsbeing formed by the corresponding groups of needles is illustrated inconnection with the circular warp knitting machine shown in FIG. 1. Thiswarp yarn feed means generally includes four sets of feed roll means,broadly indicated at A, B, C, and D. However, it is to be understoodthat a greater or lesser number of feed roll means may be supportedaround the needle cylinder 11 for separately feeding greater or lessernumbers of groups of adjacent warp yarns to the needles 12.

Each of the feed rolls means A--D includes anupper feed roll 16 and alower feed roll 17 which are suitably supported for rotation at oppositeends in vertical support posts 18 and 19, fixed at their lower ends onthe bed plate 10. The upper feed roll 16 is preferably urged downwardlyagainst the lower feed roll 17 by any suitably resilient means, such'ascompression springs 20, their lower ends riding on suitable bearingblocks and their upper ends being engaged by spring adjust ment means inthe form of screws 21 (FIG. 2).

The drive means for rotating the feed roll means A- D includes a one-waydrive clutch 21 which is fixed on one end of the drive shaft of thelower feed roll 17 of the feed roll means A (FIG. 1). The inner end ofan operating arm 22 is connected to the one-way drive clutch 21 and itsouter end is suitably connected to the upper end of a verticallyreciprocating rod 23. The rod 23 is moved upwardly and downwardly intied relationship to operation of the knitting needles and to operationof the machine by any suitable rotating cam or the like on the knittingmachine, not shown. Thus, step by step movement is continuously impartedto the lower feed roll 17 of the feed roll means A while the machine isoperating.

The opposite end of the drive shaft of the lower feed roll 17 of thefeed roll means A is provided with a bevel gear 25 which mates with thesame size bevel gear 25 fixed on the drive shaft of the lower feed roll17 of the feed roll means B. Adjacent ends of the drive shafts of thelower feed rolls 17 of the feed roll means B and C are drivinglyinterconnected by a pair of bevel gears 26, 27 which are the same size.The lower feed rolls 17 of the feed roll means C and D are drivinglyinterconnected by a speed-change mechanism, broadly indicated at 30.

The speed-change mechanism includes a first pair of bevel gears 31, 32of different sizes (FIGS. 2 and 3) fixed on drive shaft 33 of the lowerfeed roll 17 of the feed roll means D. A second pair of different sizebevel gears 34, 35 are supported for free rotation on drive shaft 36 ofthe lower feed roll 17 of the feed roll means C and are held on theshaft to prevent longitudinal movement by respective collars 40, 41which are in turn fixed on the drive shaft 36. The inner hub portions ofthe bevel gears 34, 35 (FIG. 3) are provided with beveled drive teethwhich are adapted to be engaged by the mating driving teeth on oppositesides of a shifting driver 43. The shifting driver 43 is keyed to thedrive shaft 36 and may move longitudinally between the position shown inFIG. 3, where it is drivingly engaged with the larger bevel gear 34, anda position where it is drivingly engaged with the smaller bevel gear 35.

A shifting control arm 44 engages the shifting driver 43 at one end andthe medial portion is supported for sliding movement in an upstandingsupport bracket 45. The opposite end of the arm 44 is connected to theupper end of a pattern control link 46, the lower end of which issuitably connected to a pattern control mechanism on the knittingmachine, such as a pattern drum, not shown. I

METHOD OF OPERATION In order to knit a curved tubular fabric F, such asschematically illustrated in FIG. 4, the shifting driver 43 is moved tothe position shown in FIGS. 2 and 3 so that the drive shaft 36 of thelower feed roll 17 of the feed roll means C is drivingly connected tothe drive shaft 33 of the lower feed roll 17 of the feed roll means D bymeans of the relatively large bevel gear 34 and the bevel gear 32. Then,as knitting of the tubular fabric proceeds, the groups of warp yarns W-1, W-2 and W-3 are all fed to the needles 12 at the same rate of speedand by means of the one-way clutch element 21 and the sets of bevelgears 24, 25 and 26, 27.

At the same time, the group of adjacent warp yarns W-4 is fed to theneedles 12 at a faster rate to produce enlarged or elongated stitchloops in this portion of each course of the fabric and to thereby impartthe curved configuration to the tubular fabric F, as schematicallyillustrated in FIG. 4. Since the driving bevel gear 34 is much largerthan the driven bevel gear 32, one rotation of the gear 34 will impartapproximately two rotations to the bevel gear 32 so that the group ofwarp yarns W4 is fed at a much faster rate than the remaining groups ofadjacent warp yarns W-l through W-3. Thus, the group of adjacent needleswhich knits the warp yarns W-4 forms longer or looser stitch loops thanthe corresponding groups of adjacent needles which knit the warp yarnsW-l through W-3.

The tubular fabric F (FIG. 4) has been divided into quadrants bydash-dot lines to illustrate the sections of the fabric P which are knitby the groups of adjacent warp yarns W-l through W-4. One walewiseextending quadrant 50 of the fabric F is knit by the warp yarns W- 4which are fed at a much faster rate than the remaining groups of warpyarns so that this quadrant of the fabric is longer than the remainingthree quadrants to impart a curved configuration to the fabric.

In order to knit a tubular fabric F, such as schematically illustratedin FIG. 5, having one or more enlarged pockets 51 therein, the shiftingdriver 43 is selectively moved between the position shown in FIGS. 2and3 and a position where it drivingly engages the smaller bevel gear 35.To knit a substantially: straight tubular section of fabric, with-allsets of warp yarns being fed at the same rate, the pattern mechanismmoves the con trol link 46 outwardly to impart outward movement to thecontrol arm 44 and shift the driver 43 so that its drive teeth engagethe driving teeth on the hub of the smaller bevel gear 35 to therebydrivingly connect this bevel gear 36 with the drive shaft 36 of thelower feed roll 17 of the feed roll means C. Thus, the drive shaft 33 ofthe lower feed roll 17 ofthe feed roll meansD. is driven at the samerate as the drive shaft 36 of the feed roll means C, by means of thedriving connection between the same size bevel gears 31, 35. This equalfeeding of the sets of warp yarns continues down to the dash-dot line 52in FIG. 5, where knitting of the enlarged pocket 51 is to begin.

The pattern control'means, not shown, then operates to move the shiftingdriver 43 to the position shown in FIG. 3 and to thereby drivinglyconnect the large bevel gear34 with the drive shaft 36 so that the driveto the drive shaft 33 is through the smaller bevel gear 32 and the driveshaft 33 and the lower feed roll 17 of the feed roll means D rotates ata faster rate than the lower feed rolls 17 of the feed roll means A-C.Thus, the group of adjacent warp yarns W-4 is fed at a faster rateduring the knitting of the tubular fabric F from the dash-dot line 52 tothe dash-dot line 53 to thereby form the enlarged pocket 51 in onequadrant of the fabric.

Upon completion of the knitting of the tubular A-F down to the dashdotline 53, the shifting driver 43is again shifted into engagement with thedriving teeth of the bevel gear '35 so that the driving connectionbetween the drive shaft 36 and the drive shaft 33 is by means of thesame size bevel gears 31, 35 and the lower feed roll 17 of the feed rollmeans D is driven at the same rate as the lower feed rolls 17 of theother feed roll means A-C. Since all of the feed roll means A-D are thendriven at the same rate, a straight portion of tubular fabric is knit,until it is desired to knit another pocket in the fabric.

While the warp yarn feeding method and apparatus disclosed in thepresent application is shown as being operable to increase the feed rateof one group of adjacent warp yarns, it is to be understood that thisfeeding apparatus may be utilized to vary the feeding rate of more thanone group of adjacent warp yarns, if desired. For example, thespeed-change mechanism 30 may be positioned between the feed roll meansA and B so that the feed roll means B, C, and D operate at a faster ratethan the feed roll means A. Also, the speed-change mechanism 30 may bepositioned between the feed roll means B and C so that the reed rollmeans C and D operate to feed the warp yarns at a faster rate than thefeed roll means A and B.

Thus, the present yarn feeding method and apparatus is selectivelyoperable to at times feed one or more groups of adjacent warp yarns at adifferent rate from the remaining groups of adjacent warp yarns, and toat other times feed all of the warp yarns at the same rate. Thisvariation in feed rate of the warp yarns thus permits different types offashioning or shaping of the tubular fabric to take place while it isbeing knit.

In the drawings and specification there has been set forth a preferredembodiment of the invention and although specific terms are employed,they are used in a generic and descriptive sense only, and notforpurposes of limitation.

I claim:

1. In a circular warp knitting machine including a needle cylinder withneedles supported for simultaneous vertical movement therein, thecombination therewith of means for positively, feeding a certain groupof warp yarns to the needles at one rate and another group of warp yarnsat a different rate to thereby vary the size of stitch loops beingformed by the corresponding groups of needles, said positive feed meanscomprising a plurality of yarn feed roll means surrounding said needlecylinder and adapted to each feed a group of adjacent warp yarns to acorresponding group of adjacent needles, drive means for rotating saidfeed roll means, and pattern control means for selectively controllingthe rate of feed of at least one of said feed roll means to be identicalwith or different from the rate of feed of the remaining feed rollmeans.

2. An apparatus according to claim 1 wherein each of said feed rollmeans comprises upper and lower feed rolls with the warp yarns passingtherebetween, and including resilient means urging said upper rolltoward said lower roll.

3. An apparatus according to claim 1 wherein said drive means comprisesmeans for imparting step by step movement to said feed roll means, andmeans drivingly connecting adjacent feed roll means, and wherein saiddriving connection between adjacent feed roll means includes aspeed-change mechanism said one feed roll means and an operable by saidpattern control means.

4. An apparatus according to claim 3 wherein said speed-change mechanismcomprises a first pair of bevel gears of different sizes fixed on thedriving shaft of said one feed roll means, a second pair of bevel gearsof different sizes freely rotatable on the driving shaft of saidadjacent feed roll means, and a shifting driver supported between saidsecond pair of bevel gears and being rotated with the driving shaft ofsaid adjacent feed roll means, said driver being movable along saidshaft by said pattern control means to drivingly connect one or theother of said bevel gears of said second pair to said shaft.

5. A method of positively feeding warp yarns to a circular warp knittingmachine including a needle cylinder with needles supported forsimultaneous vertical movement therein, said method comprising the stepsof positively feeding all of the warp yarns at the same rate to producea straight section of tubular fabric, feeding a group of adjacent warpyarns to a corresponding group of adjacent needles at said same rate toform stitch loops of a predetermined size, and while feeding theremaining warp yarns to corresponding needles at an increased rate toenlarge the size of stitch loops being formed by corresponding needlesand to thereby form an enlarged pocket in said tubular fabric, and thenagain feeding all of the warp yarns at said same rate to produce astraight section of tubular fabric.

Patent N .0 Dated September 26, I

Inventofls) co Sanfeliu Nogues It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

"course" to courses-;

Column. 1, Line 24, change Column 2, Line 44, change "tied" to -timedColumn 2, Line 54, change "24" to -25; Column 4, Line 6, change "36" to-35;

Column 4, Line 28, insert word --fabric following word "tubular"; Column4, Line 28, omit "A-" preceding "F'";

Column 4, Line 51, change "reed" to feed-;

Column 5, Lines 26, 2'7, 28 and 29 are to read as follows (last 3-1/2lines of Claim 3): wherein said driving connection between said one feedroll means and an adjacent feed roll means includes a speedchangemechanism operable by said pattern control means.

Signed and sealed this 20th day of February 1973.

(SEAL) Attcst:

EDWARD M FLETCHER ,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM P Q-1050 (IO-69) USCOMM-DC 60376-F'69 U,5. GOVERNMENTPRINTING OFFICE 1 i959 O365334

1. In a circular warp knitting machine including a needle cylinder withneedles supported for simultaneous vertical movement therein, thecombination therewith of means for positively feeding a certain group ofwarp yarns to the needles at one rate and another group of warp yarns ata different rate to thereby vary the size of stitch loops being formedby the corresponding groups of needles, said positive feed meanscomprising a plurality of yarn feed roll means surrounding said needlecylinder and adapted to each feed a group of adjacent warp yarns to acorresponding group of adjacent needles, drive means for rotating saidfeed roll means, and pattern control means for selectively controllingthe rate of feed of at least one of said feed roll means to be identicalwith or different from the rate of feed of the remaining feed rollmeans.
 2. An apparatus according to claim 1 wherein each of said feedroll means comprises upper and lower feed rolls with the warp yarnspassIng therebetween, and including resilient means urging said upperroll toward said lower roll.
 3. An apparatus according to claim 1wherein said drive means comprises means for imparting step by stepmovement to said feed roll means, and means drivingly connectingadjacent feed roll means, and wherein said driving connection betweenadjacent feed roll means includes a speed-change mechanism said one feedroll means and an operable by said pattern control means.
 4. Anapparatus according to claim 3 wherein said speed-change mechanismcomprises a first pair of bevel gears of different sizes fixed on thedriving shaft of said one feed roll means, a second pair of bevel gearsof different sizes freely rotatable on the driving shaft of saidadjacent feed roll means, and a shifting driver supported between saidsecond pair of bevel gears and being rotated with the driving shaft ofsaid adjacent feed roll means, said driver being movable along saidshaft by said pattern control means to drivingly connect one or theother of said bevel gears of said second pair to said shaft.
 5. A methodof positively feeding warp yarns to a circular warp knitting machineincluding a needle cylinder with needles supported for simultaneousvertical movement therein, said method comprising the steps ofpositively feeding all of the warp yarns at the same rate to produce astraight section of tubular fabric, feeding a group of adjacent warpyarns to a corresponding group of adjacent needles at said same rate toform stitch loops of a predetermined size, and while feeding theremaining warp yarns to corresponding needles at an increased rate toenlarge the size of stitch loops being formed by corresponding needlesand to thereby form an enlarged pocket in said tubular fabric, and thenagain feeding all of the warp yarns at said same rate to produce astraight section of tubular fabric.